package cn.wyj.config;

import com.alibaba.fastjson.JSON;
import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.List;

@Component
@Slf4j
public class LoginCheckFilter implements GlobalFilter, Ordered {


    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        // 从请求头中获取token,此处获取到的是一处集合
        String path = exchange.getRequest().getURI().getPath();

        log.info("login check, uri path: {}", path);

        // 如果不是登录和注册，进行下面的判断，是的话，放他走
        if (!path.endsWith("login")  && !path.endsWith("register")){
            // 拿到token,如果token是空的话，没有登录，那么直接响应没有登录
            List<String> token = exchange.getRequest().getHeaders().get("token");
            if (token == null || token.size() == 0){
                // 获取响应对象
                ServerHttpResponse response = exchange.getResponse();

                // 构建错误信息，好返回给前端
                HashMap<Object, Object> data = new HashMap<>();
                // 填上值
                data.put("code",401);
                data.put("success",false);
                data.put("message","登录校验失败，请重新登录！");

                DataBuffer buffer = null;
                try {
                    //  4.转换参数，包装buffer对象
                    // 4.1.将数据转换为JSON，再转换为byte数组
                    byte[] bytes = JSON.toJSONString(data).getBytes("utf-8");
                    // 4.2.将byte数组包装到DataBuffer对象中，用于响应给浏览器，构建响应内容
                    buffer = response.bufferFactory().wrap(bytes);

                    // 5.设置完成响应，不会继续执行后面的filter
                    // 5.1.设置响应状态为401
                    response.setStatusCode(HttpStatus.UNAUTHORIZED);
                    // 5.2.设置响应格式
                    response.getHeaders().add("Content-Type","application/json;charset=UTF-8");
                } catch (UnsupportedEncodingException e) {
                    e.printStackTrace();
                }

                // 6.把结果写给客户端
                return response.writeWith(Mono.just(buffer));


            }
        }
        return chain.filter(exchange);
    }

    @Override
    public int getOrder() {
        return 0;
    }
}
